Draft Systems Flashcards
At what rate should beer flow from a draft system tap?
1 gallon/ 128 oz/ 4L per minute
What temperature is a draft system usually kept at and what occurs if the temperature rises significantly above this level?
38 F. Increased temperature will result in a foamy beer pour
What provides resistance to beer flow as it moves through the draft system?
Draft line friction
Elevation changes
Variable resistance devices (if present)
What determines the flow rate of beer at the faucet?
The relationship between applied gas pressure and the various resistances to flow
What techniques are used to push beer long distances without over-carbonating beer?
Beer pumps: Mechanical pumps
Blending N2 into pressurizing gas
Describe the Pressure side components of a draft system
1) Gas cylinder/bulk tank: Holds beverage grade CO2 or CO2-Nitrogen mix. Bulk tanks are used by large volume gas users and refilled by trucks.
2) Nitrogen generator: Extract atmospheric N2 and fill a highly pressurized tank
3) Air compressors: Never use with traditional kegs, only with single-use kegs with internal bladders. These can be used to power mechanical beer pumps
4) Gas blender: Mix CO2 and N2
5) Beer pump: Mechanically propel beer long distances
6) Regulators: Control flow of gas. Primary regulators are attached directly to the gas source. Secondary regulators allow for different pressures to be applied to individual kegs
7) Gas lines: Thick walled tubing that can withstand high pressure. They are generally color coded
8) Couplers: Allow gas in and beer out of a keg
What are the most common coupler types?
A: German sliders. Slide onto keg rather than being rotated on
D: Most common in US
G: Grundy type. Used by some British breweries
M: German slider
S: Euro Sankey
U: English
KeyKeg: Bag-in-ball keg type. Rotates onto plastic KeyKegs
Describe the Beer side components of a draft system
1) Kegs: Can be stainless steel or plastic single-use. Protect beer from air and light
2) Coupler: Engages ball or poppet in neck of keg allowing gas to flow through into headspace of keg. Incoming gas pushes beer from the bottom of keg through the spear, through the coupler, into the line
3) Jumper lines: connect kegs to faucet shanks. Used for long draw systems to connect couplers to trunk lines and trunk lines to faucet shanks. Used in direct draw systems as a choker.
4) Foam on Beer Detector (FOB): Used in long draw systems. Canisters attached to beer lines that seal the line when the keg empties, keeping the line full of pressurized beer while changing the keg, limiting waste
5) Wall bracket: Organize beer and gas lines
6) Trunk Line: bundle of color coded beer and glycol lines wrapped and insulated
7) Beer lines: Most commonly vinyl. Stainless steel is used for jockey boxes/draft towers. Barrier tubing has a smooth glassy interior that prevents flavor leakage and spoilage
8) Draft tower: Mounts shanks and faucets
9) Beer faucet: Dispense beer and hold tap handle. Standard are rear sealing. Flow control have variable resistance devices. Nitro have restrictor plates
Describe the Cooling side components of a draft system
1) Glycol chillers: AKA Power packs or flash chillers. Cool glycol
2) Trunk lines: Bundle glycol and beer lines
